August Pest of the Month: Rhizoctonia identification and management
6 September 2024
We deliver monthly pest updates with funding from your nursery levy.
Rhizoctonia is a soil borne fungus commonly found in agricultural, forest and other natural soils worldwide. It is highly versatile and can cause a range of issues, including root rot, damping off, and fruit, stem and leaf diseases.
This fungus can cause severe damage, leading to significant yield reduction. Understanding and managing Rhizoctonia is crucial for growers to protect crop health and reduce economic losses.
Symptoms
- Rhizoctonia grows as brown, thread-like fungus, spreading through soil particles and decomposing organic matter.
- Wire stem – stems become very thin and brittle.
- Webbing blight – thick, orange, hair-like fungal growth resembling spider webs, causing plant tissue to rot.
Management and prevention
By implementing preventative measures, you can promote sustainable practices, improve crop quality and enhance plant resilience.
Preventative measures include:
- using sterilised or pasteurised soil-less potting mix
- ensuring disease-free seeds and propagative material
- maintaining optimal growth conditions, especially for seedlings (older plants are more resistant).
Additional measures include:
- protecting plants against wounding
- providing adequate spacing to prevent crowding
- managing fungus gnats in propagation areas.
Effective Rhizoctonia management ensures healthier plants and consistent, high-quality production, safeguarding growers’ investments and supporting competitive market standards.
For more information on the biology and management of Rhizoctonia, refer to the newly updated factsheet.
If you suspect your plants are infected with Rhizoctonia, we recommend you submit plants for testing. All production nurseries are eligible to receive six free diagnostic samples at Grow Help each year until the end of 2025.
